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Environment, Population, and Development Seminar Spring semester 2007 Dr. Ellen Wiegandt. Course context. Climate change is expected to have differential regional impacts Particular climate-related vulnerabilities in developing countries
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Environment, Population, and DevelopmentSeminar Spring semester 2007Dr. Ellen Wiegandt
Course context • Climate change is expected to have differential regional impacts • Particular climate-related vulnerabilities in developing countries • Particular social vulnerabilities in developing countries
Focus of course • Highlight factors leading to greater vulnerabilities • Institutions regulating resource use, especially property rights • Demographic processes and behavior
Population questions • Overview of current situation • Measurements, models, theories • Population dynamics • Particularities of developing countries
Resource issues • Agriculture • Deforestation • Links environment-population: • Migration • Health
Consequences • Regional conflict • International tensions • Migration • Negotiating positions in climate change regime
Population, environment, development nexus • Does population growth have positive or negative effect on well being? • At what spatial scale? • Over what time period?
Some questions • What is its relationship of population size and economic growth rates to economic development? • Can we define "carrying capacity" of the environment? • What is the relationship between technological change and economic growth?
Different periods; different views • Mercantilist period: population growth seen as positive to fuel commercial development • Malthus: fear that population could outstrip resources • 19th and 20th centuries: significant economic growth • Growth would spread: modernization • 1960s: concern because of unprecedented population growth: the population explosion
Actions • Stockholm 1972: first intergovernmental conference on environment • Series of conferences on population beginning in 1974 in Bucharest • Stockholm: population growth presents problems for environment • Bucharest: problem of per capita use of resources • Mexico 1984: imbalances among trends in population growth, resources, and environment • 1987 Brundtland report proclaimed goals of sustainable development, explicitly linking social, economic and environmental goals • Rio 1992 and following population conferences have reinforced this integrated approach
Population, food, and knowledge • Creation of knowledge: offset the limits imposed by natural resources by improving productivity of human capital • Evidence • Increases in real world output • Decline in number of famines • Reduction in child and infant mortality • Increased life expectancy • Reductions in time worked • Increase in percentage of population that is literate
Limits to population • In 1800 75%-80% population was rural • Life expectancy low: • 1725 in England 32 years; France 26
Changes in agriculture • New crops: maize and potatoes from new world • Enclosure movement • Fertilizer: manure • Increased yields • Consequence: decline in famines
Role of knowledge • Assumes exogenous population growth • Leads to increase in output because of necessity to intensify to keep pace with population. • As real per capita incomes increase, have specialization, including in specialization of knowledge • Larger population leads to larger increases in knowledge • More people, more likelihood of making significant discovery • New technologies provide larger relative benefits from productivity gains the larger the population
65 60 55 50 Life expectancy (years) 45 40 35 30 Changes in life expectancy in selected African countries with high and low HIV prevalence: 1950 - 2005
Essential differences Cleaver/Schreiber and Gale Johnson • Impact on resources of growth in output • Existence of externalities in reproductive choices
Unilinear evolution or different levels of well-being? • Examine environment-population-development nexus: generalities would suggest process tending toward increased well-being over time • Particular configurations that might suggest different long-term patterns could also hold
Sub-Saharan production system • Traditional system of shifting cultivation and transhumant pastoralism • Flexibility in the system came from mobility: assumed open, available land • Some population growth could be accommodated by gradual intensification • Problems emerge when population growth is too great • Parallel factor that further degrades land base: poorly defined property rights
Population dimension • Relation between per capita income and fertility; thus assume as per capita income grows, fertility will decline • Female education • Family planning • Rationale for children
Externalities • Share costs of child raising • Economic development like urbanization and mobility can erode traditional methods of social control over demographic behavior and production • State expansion can have same effect: overturn local rules of resource use • Increased resource scarcities could lead to response whereby seek more labor to meet needs: more children, more intensive exploitation of resource base
Trends, Patterns and Debates: Data, Methods, Theoretical Context • Why interested in population numbers and dynamics? • Static: count people • Taxpayers • Laborers • Potential soldiers: raise armies • Dynamic: planning • Resource issues: food supply; sufficient agricultural land • Land management: urban/rural balance • Future school population • Social security, health policy (ex. Aging) • Immigration policy
Sources of population information: Demography • Basic numbers • Distributions • Rates • Time perspective so we can look at trends • For this we need to have analytical techniques
Are numbers enough? • Link people to location • Age • Marital status • Employment • Religion, ethnicity • Literacy
Projections • Methods • Technical aspects of population: how populations behave • Data • Calculations • Underlying assumptions: theory
Population profiles: hunters and gatherers • Distinctive mode of production: use niches offered by nature • Mobile groups over wide area • Environment sets upper limits on group size • Flexible group structures to adapt to natural variation • Importance of women in food collection • Impact on fertility behavior: long intervals between births • Contemporary example: !Kung • Early marriage • Low fertility • Hypothesis: intensive nursing
Early agriculture: increased population density • Changes in level of intervention in natural processes • Possible role of climate change: Mesopotamia 10 000 BP • Warming in northern hemisphere • Greater seasonality • Changing ecology • Diversification of species. • Annual plants were favored • Human intervention in growing patterns and species • Change from nomadic to sedentary • Demographic consequences • Mortality initially increases • Population then increases: Fertility increase • Constraints on number of concurrent small children is lifted • Mechanism: shorten lactation; shorten birth intervals
Population count: census • Problems • National level • Coverage error • Content error • International level • Different interpretations of categories • Different areas/levels of aggregation • Different time periods
Vital events • Births, deaths, marriages • Used to calculate demographic characteristics and rates • Life expectancy • Infant mortality • Age at marriage • Age specific fertility rates • And therefore to be able to project population trends
Links population-social organization • Evaluate theories • Family structure-production system • Malthusian dynamics • Demographic transition • Depends on time series data and information on rates through time
Age distributions and population trajectories • Momentum in population dynamics based on size effects by generation
Affect of survivorship on potential population size Upper curve: Late 20th.C. developed country. Middle Curve: 19th. C. developed country/20th.C. less developed country. Lower Curve: City of York (England), 16-17th.C.